Weight-steered water sled



March 18, 1969 F. R. BROWN ETAL 3,433,201

WEIGHT-STEERED WATER SLED Filed Jan. 12, 1967 INVENTOR.

FLOYD R. anovm y ALTER L.FLOEl-IR WATTORNEY United States Patent 8Claims ABSTRACT OF THE DISCLOSURE A self-propelled water sled driven byan outboard motor mounted against turning astern of a drivers positionand steerable at any speed by the shifting of the weight of the driverwithout reliance upon either a rudder or directional surfaces on thehull.

The prior art While self-propelled water sleds steerable by shifting ofthe weight of the driver have heretofore been proposed, it has beenassumed that in the absence of a rudder it was necessary to rely forturning either on side skidding or on the provision of directionalsurfaces on the underside of the hull which on tilting of the sled wouldproduce a force for turning it in the direction of tilting. The first ofthese types not only is diflicult to keep on a straight course butslides oft" on turns, while the second requires a comparatively complexhull form. Too, as indicated by Sterling Patent No. 1,814,772, itappears not to have been appreciated that the position of the propellerlengthwise of the sled has any bearing upon its maneuverability.

Summary of the invention The improved self-propelled, weight-steeredwater sled of the present invention depends for maneuverability onneither skidding nor directional surfaces. Instead, it has its propelloror other propulsion means mounted to apply a pushing force substantiallyparallel to its longitudinal centerline, has longitudinally extendingside keels on the underside of its hull at opposite sides of thecenterline and makes use of relative drag on above and underwater partsof its hull for producing with the pushing force a turning force ormoment in the direction toward it is tilted and of the keels for bothmaintaining it on a straight course when level and controlling its turnswhen tilted.

The preferred sled has a hull that is substantially flatbottomed andsided and has an upturned bow for better riding at low speeds. Thesimplicity of line readily adapts the hull for forming of fiber glass orother suitable material and, even with so simple a hull, the sled iseasily maneuverable at low speeds and increases in maneuverability athigher speeds with increase in the water drag on the down-tilted side.

It therefore is an object of the present invention to provide aself-propelled water sled which, while turnable solely byweight-shifting, is uncomplicated in construction and readilymaneuverable at any speed.

Other objects and advantages of the invention will appear hereinafter inthe detailed description, be particularly pointed out in the appendedclaims, and be illustrated in accompanying drawings, in which:

Figure description FIGURE 1 is a plan view of one of the counterparthalves of a preferred embodiment of the improved water sled of thepresent invention;

FIGURE 2 is a side elevational view of the sled of FIGURE 1; and

FIGURE 3 is a front elevational view of the sled of the precedingfigures.

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Detailed description Referring now in detail to the drawings in whichlike reference characters designate like parts, the improvedself-propelled water sled of the present invention is comprised of ahull 1 made of suitable material. The preferred hull is both hollow andwatertight and made of glass fiberreinforced epoxy or like plastic,commonly known as fiber glass. When made of fiber glass, the hullconveniently is formed of separately molded upper and lower parts 2 and3, respectively, having a flanged joint at which they are bonded orotherwise suitably joined together, the illustrated joint extendingaround the hull below the gunwale 4 to form a projecting rub rail orbumper 5.

In shape the preferred hull 1 is generally square-ended andflat-bottomed, with an upand in-turned bow 6 for better riding at lowerspeeds. Making of the hull is facilitated and maneuverability of thesled improved, if the bottom or underside 7 and sides 8 of the hull aresubstantially fiat over most of the hulls length from a point forward ofamidships to the preferred square stern 9. While exact flatness ispermissible, the substantial flatness of the illustrated embodiment inwhich the bottom 7, longitudinally and laterally, and the sides 8,longitudinally, have a slight outward or convex curvature or rounding,is preferred for both increased strength and easier molding. Bothconvergence and extensive flairing, upwards, of the sides 8 will have anadverse effect upon the sleds maneuverability and for optimumperformance the sides should be substantially vertical with any upwardfiair slight.

For the sled to operate as intended, the hull 1 needs no center keel butmust have side keels or fins 10 on its bottom 7 at opposite sides of itscenterline. While there may be a plurality on each side, the illustratedpair of side keels 10, one to a side, will usually be adequate. Whateverthe number, the keel or keels on each side should be sufficiently spacedor offset laterally from the centerline toward the adjoining side to beat least partly submerged at all speeds when the hull in turning istilted toward that side and also should extend both fore and aft of thesleds center of gravity. The keels downstand vertically from the bottom7 and are quite shallow, a depth on the order of that of the center keelof a power boat of comparable dimensions usually sufiicing. The width isunimportant except as necessary to resist the lateral forces encounteredduring turning. However, the keels, longitudinally, must be parallel tothe hulls longitudinal centerline and should also be straight, if, asintended, one or the other is to enable a turn to be controlled and bothare to cooperate in holding the sled when level on a substantiallystraight course. Too, by making their bottoms 11 flat and coplanar, thekeels are enabled to act as skids on which the sled can be rested andslid when out of water. Even though shallow, to the extent of theirdepth the keels also increase the area of the hull exposed to dragduring turning.

To shed water coming over the bow 6, the sled prefer ably has a turtleback or arcuately convex foredeok 12. A cowling 13, rising or upstandingfrom the rear or aft part of the foredeck 12, is useful for housing andshielding or protecting a gas tank 14 and, for engine starting, battery15, which are held in place in seats 16, the latter in the case of thepreferred fiber glass hull 1, conveniently being molded into the upperpart 2. The main part of the hull, from a point forward of amidships tothe stern 9, is decked or covered by a main deck 17, suitably flat, ifas will usually be the case the sled is designed to be operated by astanding operator or driver. The main deck is protected at the sides bycoamings 18 merging forwardly with the cowling 13 and extending afttherefrom to the stem 9. The roughly amidships forepart 3 of the maindeck 17 is the platform or stand 19 on which the operator stands inoperating or running the sled and at least this part of the main deckpreferably is antiskidsunfaced.

For holding himself in position, the operator is provided with a holdbar or hand hold 20 extending laterally of and parallel to the main deck17. Conveniently, the hold bar 20 is the cross-member of a handle 21 ofinverted U-shape, the legs 22 of which, serving as the hold barsstanchions, are socketed or received at their lower ends in mountingbrackets 23 fixed to the foredeck 12 at opposite sides of the cowling13. As desired, the hold bar 20 may be fixed or adjustable in position,both fore and aft, any vertical adjustment to suit a particular operatorreadily being providable by mounting the legs 22 in the brackets 23 forfore and aft swinging to any of a plurality of positions with means (notshown) for locking them in selected positions.

As important to the maneuverability of the sled as the side keels is thelocation of the propeller or other propulsion element 24. In contrastwith prior teachings, such as that of the Sterling patent, it is vitalthat the propeller have a fore and aft location aft of the sleds centerof gravity, so as to push rather than pull the sled. The propeller isfixed against horizontal angling or turning relative to the hull 1 and,if the sled is to'turn equally well in both directions, also should becentered laterally on the hull. Most suitably, the sled is driven by anoutboand motor 25 and the requirements for propeller location are met bymounting the motor in or at the stern either on the stern transom 26 or,as shown, in a rearwardly opening well 27 centered laterally on the hulland interrupting and projecting forwardly of the transom. The motor 25may be clamped in the usual manner to the hull for rearward swinging toyield to an underwater obstruction, but, as opposed to the usualpractice, will be locked or held, suitably by the usual inbuilt latch(not shown), against horizontal angling or turning relative to the hullin a center position in which the propeller is directed to apply itspushing force substantially parallel to the'hulls longitudinalcenterline. While the longitudinal and lateral or transverse location orposition of the propeller 24 relative to the sleds center of gravity isall important, it also is important that the propeller be so locatedvertically relative to the center of gravity as neither to drive the bow6 down nor to tend toflip the sled over on its back.

Control of the action of the motor 25 is exercisable by the operatorfrom a standing position on the platform 19 by mounting on a panel 28 onthe handle 21 below the hold bar 20 one or more control levers suitablyconnected to the motor. In the illustrated embodiment a single controllever or bar 29 serves to control all of the actions, the lever Ibeingrotata ble in opposite directions for forward and reverse and swingablevertically for controlling speed. As an operator who fell off the sledcould well be injured if the motor thereafter continued to run, thecontrol lever 29 also serves as a deadman lever by being springloaded toswing to a down position in which it shorts the motor the moment it isreleased by the operator.

The buoyancy of the hull 1 will depend on the size of the motor andnumber of occupants for which the particular sled is designed. In anycase, for low speed maneuvering, the hulls buoyancy should be such as tosupport the load for which it is designed with the main deck 17 abovewater level or not awash. This dependency for floatation upon hullbuoyancy will decrease with increase in speed, at which time the higherpropulsive force of the propeller 24 will cause the hull to plane on itssubstantially flat bottom 7 with its bow 6 lifted above water.

The drag of water on the submerged or underwater part of the hullrelative to that of air on both the abovewater part of the hull and theoperator, will increase with increase in speed. The propeller 24 becauseof its location applying a pushing force at least aft of and preferablyalso in substantial longitudinal alignment with the center of gravity,and the main reactant to that (force, the drag of water on the submergedpart of the hull, progressively shifting with increase in tilt away fromthe center of gravity toward the down-tilted side, the sharpness of aturn at any speed will be determined by the degree of tilt. Moreover, asthe water drag increases more rapidly than the speed and thisdisproportionate increase is only partly compensated by planing, thesensitivity of the sled to weight-shifting by the operator and itsresponse thereto in turning or maneuvering will increase with increasein speed. However, while it is the eccentricity of the applied and mainreactant forces that produces the turning force, if only the latter wereinvolved, the tendency of the sled would he to spin or side slip ratherthan turn and this tendency would increase with increase in speed. Thistendency must be resisted if the sled is to be maneuverable orcontrollable in its turns and it is this function that is performed in aturn by one or other of the side keels 10. Partly or fully submerged,depending upon the extent of planing, the side keel on the down-tiltedside tends, because of its straightness and longitudinal dispositionrelative to the hull, to hold the sled upon a straight course inopposition to the turning force and makes it possible for an operatorreadily both to turn the sled at will and control the extent of theturning.

From the above detailed description it will be apparent that there hasbeen provided an improved self-propelled water sled which is readilymaneuverable at any speed simply by weight-shifting. It should beunderstood that the described and disclosedembodiment is merelyexemplary of the invention and that all modifications are intended to beincluded that do not depart from the spirit of the invention.

Having now described our invention, we claim:

1. A self-propelled water sled, rudderless and maneuverable byWeight-shifting, comprising a single hull on which the sled entirelydepends for buoyancy, propulsion means mounted on and fixed againsthorizontal angling relative to said hull and located aft of a center ofgravity of said sled, straight side keel means on an underside andextending longitudinally of said hull at opposite sides and parallel toa longitudinal centerline thereof andv fore and aft of said center ofgravity, said side keel means on each side of said centerline being sospaced laterally therefrom as to be at least partly submerged ondowntilting of said hull toward said side, a deck at least partlycovering a top of said hull and longitudinally overlapping and extendinglaterally between said side keel means, and means projecting above saiddeck for enabling an operator to support himself in standing positionthereon, said sled depending for controlled turning on the cooperativeaction of the side keel means and relatively greater frictional drag onthe down-tilted side of said hull under the force applied by saidpropulsion means.

2. A water sled according to claim 1, wherein the hull aft of a bowthereof has a substantially flat bottom and the side keel means arefixed to and downstand from said bottom toward opposite sides thereof.

3. A water sled according to claim 2, wherein the propulsion means arepropeller means of outboard motor means.

4. A water sled according to claim 3, wherein the motor means is astern-mounted outboard motor centered laterally on the hull.

5. A water sled according to claim 1, wherein the side keel means are apair of side keels fixed to the hull at opposite sides of thelongitudinal centerline thereof.

6. A water sled according to claim 5, wherein the side keels have flatcoplanar bottoms.

7. A water sled according to claim 4, wherein the motor is mounted in arearwardly opening well in and centered laterally on a stern of thehull.

8. A water sled according to claim 1, wherein the hull is formed ofseparately molded upper and lower glass 5 6 fiber-reinforced plasticparts and the parts have a flanged 3,213,822 10/ 1965 Sawchuk 11570joint forming a rub rail around the hull. 3,340,845 9/1967 Tyrack 11570References Cited FOREIGN PATENTS UNITED STATES PATENTS 5 795,194 5/1958Great Britain. 2,744,267 5/1956 Roby 115-70 X 2,828,491 4/ 1958 Turgeon11570 TRYGVE M. BLIX, 'Primary Examiner.

